Evaluation of the North Sea joining in situ and remotely sensed
data with model results

R. DOERFFER, W. PULS, D. PAN, H.-H. ESSEN,
K.-W. GURGEL, K. HESSNER, T. POHLMANN, F. SCHIRMER,
T. SCHLICK
In: Sündermann, J. (Ed): Circulation and contaminant fluxes in the
North Sea,
Springer, Berlin, Heidelberg, New York, pp. 434...457, 1994.
Abstract - -
The complicated distribution and the rapid changes of water masses in the North
Sea make it difficult to interpret data of ship survey cruises as quasi
synoptic observations. Isoline maps of any concentrations derived from cruises
of several weeks' length do not show an actual situation but a mixture of the
sparial distribution as well as the temporal development, which can not be
separated from each other. The plotted distribution includes effects of
phytoplankton growth and the advective transport of water bodies with different
constituents.

In chapter 4.7 Bohle-Carbonell analyzes the ZISCH-STAR cruise data set with
respect to these shortcomings of ship observations. One possibility to improve
the signification of observations is the additional use of remote sensing
data. Which respect to the overall goal of the ZISCH project, the remote
determination of water constituents, particularly of suspended matter and of
the currents which determine the distributon of water masses, was of major
interest. Thus, during the ZISCH experiments, case studies were carried out
employing the following two remote sensing techniques in order to assess their
potential for scientific investigations and operational monitoring programms:

Satellite remote sensing of water constituents based on measurements of the
backscattered solar radiation within different bands of the visible spaectral
range (data of the CZCS, satellite NIMBUS 7);

Ground based remote sensing of surface currents based on the backscattering
of high frequency (HF) radio waves, which are transmitted and received from
coastal stations (with CODAR system).

Within this chapter, results of both remote sensing techniques will be
presented and compared with ship observations and model calculations.